Steam boiler



C. J. GAL'LOWAY.

STEAM BOILBR. N0. 253,365. Patented Feb. 7,1882.

UNITEE STATES PATENT OFFICE. f

CHARLES J. GALLOWAY, OF MANCHESTER, COUNTY OF LANCASTER,

' ENGLAND.

STEAM-BOILER.

SPECIFICATION forming part of Letters Patent No. 253,365, dated February "7, 1882. Application filed March 8, 1880. (Model.) atented inl England January 14, 1876.

have invented an Improvement in Steam-Boilers.; and I do hereby declare that the following description, taken in connection with the4 accompanying drawings, hereinafterv referred to, forms a full and exact specification of the same,'wherein I have set forth the nature and principles of the said improvements by which myinvention may bedistinguished from others of a similar class, together with 'such parts as I claim and desire to secure by Letters Patent-that is to say:

My improvements relate more particularly to the construction of steamboilers now generally known as Galloway77 boilers, in which one or more internal dues, either of a circular, elliptical, or other curved form, are provided, having tapering transverse water-tubes fixedtherein. The said improvements are, however,

equally applicable to `all single or double, in-l ternal-lued, or Cornish boilers. -In such boilers, when the internal flue or fines are continued of their full diameter to the back plate of the boiler, the rivetsthat secure them to the back plate approach at one point orat two points of the circumference so near to the rivets that secure the back plate tothe cylindrical shell that no sufficient surface of back plate intervenes .between the two lilies of riveting to allow freedom for expansion and contraction of the flue without straining the rivets, and in consequence thereof a leakage frequently occurs at the rivet-holes at those joints. Now, according to my present invention. I obviate .this defect by stopping short the due at the point or points where itapproaches nearest the cylindrical shell ot' the boiler, and connecting it to the back plate at such point orpoints by means of a bent plate of such a forml that it fits the'cylindrical or other curved surfaceof the flue and then curves inward away from the cylindrical shell and is riveted with a straight or slightly-curved flange to the back plate at some distance from the shell.A The hole in the back plate for the tlue is thus made to present the form of'a circle, ellipse, or other curve,with a segment orsegments cut oft' at the point or points where it approaches nearest the cylindrical shell. By this arrangement suflicient surface is provided in the back plate to allow freedom of expansion and contraction for the flue without straining the rivets, in addition to which the curved form oftthe connecting plate or plates also allows it or them to yield somewhat as the flue expands or contracts, so that the whole strain is not put upon the back plate.. According to another arrangement I stop the entire circular or-other shaped ue v short ot' the back plate, and Iconnect the two parts by means of a solid welded iron ring that titsthe flue at one end and then curves inward all round, so as to t with a'flange against a hole of sufficiently-reduced size in the back plate.

Figure l represents a transverse section, and Fig. 2 a sectional plan, of a boiler having .two cylindrical dues to which my invention is applied; and Fig. 3 represents a transverse fsection, and Fig. 4 a sectional plan, showing its applicatian to a boiler having a line of the kind described inthe specification to Letters Patent granted to me, the said C. J. Galloway,

'and C. H. Holt on the 8th of August, 1876,

Referring to Figs. l and 2, it will be seen that the ends of the flues at the sides next the outer casing are connected to the end plate of the boiler by curved portions bent inward, which may either be made in one piece with the body ofthe due, as shown at A, or maybe a separate piece, as shown at B., InfFigs. 3 and 4 a like construction is shown, vthe bentin portion of the'tlue being either in one piece with it, as at C, or being a separate piece, as'v at D.

It is obvious that a bent piece, such as B or D, instead of extending Vpartially round the ue, might be carried entirely round it.

Having thus described the nature of' my invention and in what manner the same is to be performed, I claim- A boiler-liuc constructed at its'end substantially as described, whereby the distance between the shell of the boiler and the edge of the opening through the head is increased at one or more places, for the purpose specified.

In witness whereof I, the said CHARLES JOHN GALLOWAY, have hereunto set my hand and seal this 12th day of February, in the year of our` Lord 1880.

CHARLES JOHN eAttoWAr. p.. si

IOO 

